


sisterly bonding

by WattStalf



Series: Commissions [225]
Category: Kill la Kill (Anime & Manga)
Genre: Dom/sub, F/F, Omorashi, Rimming, Shoe Fucking, Sibling Incest, commission
Language: English
Status: Completed
Published: 2020-10-29
Updated: 2020-10-29
Packaged: 2021-03-09 01:29:32
Rating: Explicit
Warnings: Creator Chose Not To Use Archive Warnings
Chapters: 1
Words: 3,015
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/27266488
Author URL: https://archiveofourown.org/users/WattStalf/pseuds/WattStalf
Summary: Satsuki and Ryuko have their ways of being close now.
Relationships: Kiryuuin Satsuki/Matoi Ryuuko
Series: Commissions [225]
Series URL: https://archiveofourown.org/series/1325462
Comments: 1
Kudos: 25





	sisterly bonding

Ryuko can’t remember the last time she had to pee this badly, and has no idea just how long she can hold out like this. The longer the better, she knows, but she also knows that there is no way that Satsuki is going to let her off the hook, and there is no way that she is going to be able to hold out indefinitely.

For Satsuki, this sort of thing is essential, and for Ryuko, it is a steady process of coming to terms with just how submissive she really is, and how much she wants her older sister to take control of her, to let her relax and give all of her control over to someone else. It is hard to feel like they are sisters, when they spent their lives apart, and now, the only way that they can bond is in this peculiar way, where Satsuki is able to live out her more dominant impulses, and Ryuko can accept her submissive side, letting the girl she used to freely mouth off to have her way with her.

So today she has to hold it as long as she possibly can, the longer the better, but she also knows that it will all amount to nothing in the end, because Satsuki is going to get her way, and that means that Ryuko is going to end up pissing herself. And while she is left naked, Satsuki is dressed to the nines, ready to stand over her and humiliate her, to degrade her and to use her. And Ryuko, despite herself, is going to love every second of it, because she always does, and can never resist being treated like this.

“Get on your back,” Satsuki commands her, and Ryuko does so, wanting to hesitate, maybe even mouth off a bit, but she knows better than to do so, and decides to just be compliant, for now and until the end. She is going to give in no matter what, whether she fights it or not, and she is slowly realizing that it is easier to swallow her pride from the start, to just give in as soon as Satsuki starts ordering her around, and then she can enjoy herself that much more. There really is no denying the fact that she wants this, so she has no idea why she sometimes wants to fight it so hard.

She lays down, and Satsuki stands over her, giving her a sharp glare as she looms. Ryuko is so used to being looked down on by Satsuki, and she used to hate it. She never would have thought that she would end up in a position like this, willingly lowering herself so that Satsuki could do something like this to her, and she certainly never thought she would willingly let Satsuki step on her. Factor in her bursting bladder, the amount that Satsuki made her drink while telling her that she would not be allowed to relieve herself, and all of this seems like something she never, ever would have willingly done, but here she is, entirely willing, no matter how reluctant she may be to admit that.

She worries that Satsuki is going to go for her bladder first and foremost, just to see what she can endure, to see if she can make her piss herself right off the bat, but she holds back there, and instead steps on Ryuko’s chest, right between her breasts, pressing her foot down as she comments, “This is exactly where you belong.” It is the same speech each time, and Ryuko never tires of it, even if she might sometimes pretend that she does.

It never ceases to amaze her just how quickly she was able to give into this, how quickly things changed once she and Satsuki were together. Her infatuation with her long lost sister quickly took over her life in ways that she never could have expected, in ways that left her flat on her back, letting her sister dig her heel into her chest, just to make her gasp breathlessly.

“Pathetic,” Satsuki says, her scowl starting to shift into a more triumphant smirk. She will win this time, because she always wins; Ryuko always lets her win, never putting up a fight, because she needs to be in this position just as much as Satsuki needs to be in _that_ position. Slowly, she lifts her foot, bringing it to Ryuko’s face as she nudges at her lips with the heel. “Suck on it.”

And so she does, wrapping her lips around the heel of her shoe, eagerly sucking on it, getting much too into it to ever be able to pretend that this is not exactly what she has been wanting. It thrills her to be degraded like this, to suck on the heel of Satsuki’s shoe like she is sucking a cock, putting her all into it until Satsuki is finally satisfied with that and says, “Now, you are to clean my shoe with your mouth. Once you’re done with that, I expect you to do the same with the other, and then we’ll see if you’re worth rewarding by dirtying them again.”

Ryuko knows exactly what that means, and it sets her heart racing. It is easy to forget that her bladder feels like it might explode from how full it is when she is made to lick Satsuki’s shoes clean, when she knows that she will be rewarded if she does a good enough job, that Satsuki will use her heels to fuck her. No matter how tough she tries to act in her day to day life, it all falls apart once she is on her back, because she is willing to let Satsuki do anything to her, and she loves it all, _needs_ it. There is probably nothing more pathetic than being that desperate to get fucked by the heel of her older sister’s shoe.

There is nothing that she wants more.

Her tongue works its way along the sole of the shoe, immediately submitting to the orders, not holding anything back. She licks it all over, over and over again, thoroughly until Satsuki finally pulls it away, and puts the other heel over her face, where Ryuko can begin the process all over again, starting by sucking on the heel again. All the while, Satsuki looks down at her, so cold and disdainful, as if her own little sister is lower than garbage, as if she is little more than the very dirt that she is now using her tongue to clean up.

But still she works as diligently as she can, and once she is done sucking, she is licking again, hoping desperately that this will be enough to earn her her reward. Satsuki has never denied her that before, of course, but each time, there is still that same worry that this might be the time that things change, that Ryuko finds some way to let her down, not managing to meet her standards no matter how hard she might work at it.

Soon enough, Satsuki is pulling this foot away as well, and inspects her shoe, before nodding. “That was very good work, but I would expect no less from a slut like you. This is all that you are good for, after all, and it would be pretty sad if you weren’t able to do a satisfactory job at the one purpose that you have. Now, since you did as good as I wanted you to, I suppose I can finally give you the reward that I promised.”

But rather than putting her foot between Ryuko’s legs, she starts stepping on her upper stomach, pushing the toe of her shoe down a bit. She gives Ryuko a look, one that suggests she is still toying with her, and she realizes then exactly what Satsuki’s goal is. After all of the work that she has put into holding back, Satsuki is not going to allow her to hold it anymore, no matter how hard she might have been willing to fight it. There will be nothing that she can do once Satsuki’s shoe starts to move lower, no way that she can fight against the pressure added to her already bursting bladder. She has spent so long fighting it, but this is going to be much more than she can handle.

“I’m sure you can’t withstand this, no matter how hard you may try,” is what Satsuki says to her, as she starts to push down, moving down each time she lifts her foot again, until finally, she is bringing the toe of her shoe down directly onto Ryuko’s bladder. She winces and cries out. “What, is that really too much for you?”

“You already know…you already know that I…” Ryuko tries to gasp out, but she can’t even bring herself to finish her sentence, and she is cut off, sent into another loud groan as Satsuki applies more pressure again, and this time, Ryuko can’t stop a jet of urine from leaking out of her.

Satsuki _tsk_ s and shakes her head. “You really can’t. That’s so pathetic. Are you going to piss yourself? You can’t hold it under the circumstances?”

“Not with you stepping on me like that,” she mutters, and Satsuki applies more pressure to make her cry out again, to cut off anything that she might try to say. That is finally too much for Ryuko to handle, and this time, it is not just a spurt leaking out. Instead, she loses control completely, moaning in a mixture of relief and humiliation as she pisses herself, a puddle growing on the floor beneath her, Satsuki’s foot still on her stomach, her sister glaring down at her with so much disappointment. It only serves to turn Ryuko on that much more, being put in a situation like this.

“Honestly, I shouldn’t reward you after a display like that,” Satsuki says, shaking her head. “But since I already promised that reward to you, I don’t want to go back on my word. You’re going to have to suck this heel clean when I’m done with you though. You’re about to make it so filthy again.”

Now, she rests her foot right on Ryuko’s cunt, and pushes back and down, her heel slipping back until Ryuko can feel it prodding at her. She gasps and moans, and can’t help but mutter, “ _Please_ ,” just before Satsuki uses it to penetrate her, pushing it inside of her and earning a long, loud moan from her pathetic sister. Ryuko loves this, loves it so much more than she knows that she should, and there is nothing she can do but take it, until the entirety of the heel has disappeared inside of her.

Satsuki is never gentle when she fucks her, but at this point, Ryuko is more than able to handle it, and she craves it. She craves how rough Satsuki gets as she fucks her with the heel of her shoe, thrusting it into her, making her moan out while she continues to hurl insults, making sure that Ryuko understands just how pathetic she looks from where Satsuki is standing. And Ryuko takes it all, hiding nothing now, so lost in her pleasure that she can’t hold back, she has to let every pathetic part of her shine through.

This is how the two of them have bonded; this is something that only the two of them share, that neither could ever share with anyone else. Satsuki is the only one that Ryuko will let handle her like this, and in that way, Satsuki is the only one who can satisfy her, the only one who can give her what she really needs. She is always going to be this pathetic, getting off on being degraded by her older sister, and then fucked by the heel of her shoe, treated like she is lower than dirt, loving every second of it.

It never takes long like this, especially not after all of the teasing that Ryuko has endured up until this moment. Truth be told, even the feeling of her bladder finally emptying was so orgasmic that it nearly sent her crashing into her climax, so now she is at the point that she can barely hold out, only waiting because she wants to hear Satsuki tell her to do it. She not only wants permission, but she wants it to be an order, something that she has no choice but to do.

Holding back is difficult, but she has her practice with ignoring the way her body aches for this kind of release, a need that somehow seems more intense than even her bursting bladder did. If she thought she needed release then, it is nothing compared to what it feels like now, wanting so badly to come, and only wanting it that much more when she looks up at the cold expression on Satsuki’s face as she uses the heel of her shoe to fuck her little sister’s pathetic, needy cunt.

“Are you already on the edge? First you piss yourself, then you show just how needy you really are, how much you love to be degraded like this,” Satsuki chides her, and Ryuko moans out, the only response that she is capable of in the state that she is in. Oh, it is all too much for her, and she has no idea how she is supposed to withstand all of this, or how anyone could think it strange that this is all it takes to get her off. She can’t imagine anyone being able to resist this, being able to resist her old sister, and her cold and calculated treatment.

It is while she is thinking about all of this, while she continues to fight off her own orgasm, that Satsuki calls her name, and she looks back up at her again, their eyes locking, and Ryuko getting caught up in her sister’s icy expression. “If you’re that pathetic, then I suppose it can’t be helped. Go ahead and come for me, right now.”

Ryuko does not need to be told twice, and that is one order that she can follow without hesitation, crying out so pathetically as she comes, her body wracked with spasms beneath Satsuki’s foot as she comes hard, and Satsuki continues to fuck her all the way through her orgasm, as if to see just how much she can prolong it. It is everything that Ryuko could have asked for and more, bliss like she has never known, and bliss that she will never know anywhere else but where she belongs- on the ground, beneath her sister’s heel, lower than dirt, and belonging entirely to her.

Slowly, she pulls her heel back out, and takes a moment to stand straight and steady herself, before she is bringing it over Ryuko’s face again. “Now, you need to take care of the mess that you have made. I gave you your reward, but you made a mess of me again, as a result. I know I don’t need to tell you what to do, though.”

“Right…” Ryuko breathes, unable to do anything but agree before she starts sucking on Satsuki’s heel, the heel that was just pressed inside of her, fucking her absolutely senseless. She can taste herself on it, and that makes her moan even more, the humiliation of this act not lost on her, and making it that much better for her, as she gives into even more of her pathetic impulses.

She is eager as she sucks on it, just as eager as she was when they started, always full of energy when it comes to being humiliated like this, when it comes to proving just how far she will sink. This is the way the two of them bond, with Ryuko simply serving to show her love, while Satsuki shows her love through control. When she is satisfied, she pulls her heel from Ryuko’s mouth, and steps further forward, until she is standing directly over Ryuko, where she can look up her skirt and see that Satsuki is not wearing any panties.

“I don’t need to tell you what to do,” Satsuki says, as she squats down to sit on her sister’s face, and it is true that she does not need to. Ryuko knows exactly how to please her, quickly pressing her tongue up, licking along Satsuki’s asshole, teasing her like this before pushing it in, working it inside of the tight hole, and listening to the low moan that Satsuki lets out like this.

Ryuko has gotten very good at eating her big sister’s ass, with a lot of experience in doing so. Whenever Satsuki sits on her face, she knows that this is what Satsuki expects of her, so she is always quick to get into it, working her tongue inside of her to make her moan more and more, doing everything in her power to please Satsuki, to make sure that she feels amazing in return for all of the things that she has done for Ryuko. It is by far the least she can do to repay her for all of the degradation, the humiliation that she has come to love more than anything in the world.

They both have their needs, and they can both help the other with those needs, just like any good sister would. The two of them bond like this, helping the other reach the heights that they can’t reach alone, and it does not take Ryuko very long to have Satsuki screaming out in absolute bliss as she comes just from having her ass eaten by her little sister. She remains on top of Ryuko for the moment, riding out her orgasm, enjoying every moment of it, until she is finally able to stand on her own. This time, she helps Ryuko to her feet.

“You’d better get to work,” she says. “You’ve made quite the mess that needs cleaning up.”

**Author's Note:**

> If you're interested in my writing updates, please follow my fanfiction twitter @WattStalf  
> 


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